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Proposal No. XRH-CQ50-2026-01 · V1.0 Download PDF
PROCESS DESIGN & QUOTATION · 50 t/d

Process & Quotation Plan for a 50 t/d Food Waste Plant

Based on the process flow diagram you provided: enclosed collection & transport → high-pressure hydraulic pulping → cyclone grit removal → constant-temperature heating → three-phase centrifuge oil extraction → hydrolysis/acidification → mesophilic anaerobic digestion → dry desulfurization & gas storage → biogas power & heat generation → bio-deodorization. This plan gives the full-process mass balance, an item-by-item equipment list with pricing, and operating-cost and payback calculations. The quotation covers only the treatment equipment in the flow diagram, and excludes civil works, buildings, tanks and utilities.

50t/dCapacity · 330 operating days/yr
950.6010k RMBTotal equipment price (incl. 13% VAT)
3,000m³/dBiogas output (CH₄≥60%)
1.8t/dCrude oil/grease output (for sale)
Prepared by: Zhucheng Xinridong Machinery Factory Date: 2026-10-17 Equipment items: 39 Pricing basis: incl. 13% VAT
OVERVIEW

Overview

A 50 t/d food waste plant using the full route of hydraulic pulping + three-phase oil extraction + mesophilic anaerobic digestion + biogas CHP. Waste goes in, and three things come out: sellable crude oil/grease, on-site power and heat, and treated water and emissions that meet discharge standards.

Total equipment price
950.6010k RMB
39 items · incl. tax · civil works excluded
Investment per capacity
19.010k RMB/(t·d)
Equipment only, at 50 t/d
Annual operating revenue
866.3510k RMB
Grease + biogas power + tipping fee + digestate
Static payback
2.0years
On equipment price · tipping fee RMB 180/t
Plant power use
5,500kWh/d
Biogas generation 6,000 kWh/d; self-use covers demand
Operating cost
233.8RMB/t
Excl. depreciation and financing; incl. power, water, chemicals, labor, maintenance
Full cost
272.2RMB/t
Incl. 15-year straight-line equipment depreciation (RMB 38.4/t)
On the basis: this plan is the full process (including anaerobic digestion and biogas power), so the operating-cost basis differs from the "pre-treatment oil line RMB 160–200/t" shown on the homepage — the latter excludes digestion, biogas and digestate treatment. If only the pre-treatment oil-extraction stage is built (no digestion), equipment investment can drop to ~RMB 3.5–4.0 million, but ~55 m³/d of organic slurry will then need separate disposal.
DESIGN BASIS

Design basis & feed conditions

The following are typical design values for a 50 t/d project. Before detailed design, we recommend continuous sampling over 3–5 days to test moisture, oil content and impurity rate, and to reconfirm equipment sizes accordingly.

Feed conditions

FEEDSTOCK
Treatment capacity50 t/d16,500 t/yr (330 days)
Feed sourceHotels, restaurants, canteens of institutions and schoolsMostly food waste (swill)
Moisture content75–80%Design value 77%
Oil content3–4%Design value 3.5%
Impurity rate3–5%Plastic, utensils, glass, metal
Collection modeEnclosed transfer truck5-t trucks, ~10 trips/day
Receiving hours6:00–18:00Peak 6 t/h

Key design parameters

KEY PARAMETERS
Pulping concentration10–12%High-pressure combined hydraulic pulping
Grit after removal≤0.5%Protects the centrifuge drum
Oil-extraction heating temp70–80℃Demulsification in constant-temp tank
Three-phase capacity10–12 m³/h2 units, one duty one standby
Hydrolysis/acidification HRT~4 days250 m³
Digestion temp / HRT35±2℃ / 22 days2×1000 m³ mesophilic
Volumetric load4.0 kgCOD/(m³·d)Biogas 0.40 m³/kgCOD
Odor air volume25,000 m³/hScrubbing + biofilter
Applicable standardsCJJ 184-2012 Technical Code for Food Waste Treatment; GB 14554-93 Emission Standard for Odor Pollutants, Grade II
PROCESS FLOW

Process flow

Implemented exactly per the flow diagram you provided, in six stages. Blue marks key equipment and green marks outputs. Each stage notes the corresponding design parameters and material routing.

①

Receiving & pulping

MECHANICAL PRE-TREATMENT
Enclosed food waste transfer truck▸Enclosed receiving hopper (negative-pressure odor control)▸High-pressure hydraulic pulper
mechanical shearing + hydraulic scouring
▸Raw-slurry buffer tank
homogenizing, tempering, anti-sedimentation

Feed 50 t/d, peak 6 t/h; slurry concentration 10–12%; inorganic impurities are separated and removed here.

②

Grit removal

SAND REMOVAL
Slurry feed pump▸High-concentration cyclone grit remover▸Overflow: cleaned organic slurry

Underflow fine grit → screw press dewaterer → cake removed off-site; filtrate returns to the buffer tank. Grit after removal ≤0.5%, protecting the downstream centrifuge.

③

Heating & three-phase oil extraction

HEATING & 3-PHASE SEPARATION
Constant-temp heating reactor
70–80℃, demulsification
▸Three-phase horizontal disc centrifuge

Separated into three streams: crude oil/grease → insulated oil tank → sold; high-purity organic slurry → hydrolysis/acidification; fine bottom residue → returns to buffer tank for re-pulping.

④

Hydrolysis/acidification & mesophilic digestion

HYDROLYSIS & ANAEROBIC DIGESTION
Hydrolysis/acidification tank
250m³, HRT≈4d
▸Mesophilic anaerobic digester
2×1000m³, 35±2℃, HRT≈22d
▸Biogas collection▸Gas-water separator

High-purity organic slurry 55 m³/d goes to digestion at a volumetric load of 4.0 kgCOD/(m³·d), yielding biogas 3,000 m³/d (CH₄≥60%); digestate 52 m³/d is removed for land application or discharge.

⑤

Biogas upgrading & utilization

BIOGAS UPGRADING
Dry desulfurization tower
H₂S≤20ppm
▸Double-membrane gas holder
1500m³ constant pressure
▸Biogas distribution valve group

In two streams: biogas hot-water boiler 1.4MW → hot-water loop → digester and heating-tank insulation; biogas generator set 250kW → plant electrical system, self-generated for self-use, waste heat recovered for digestion heating.

⑥

Odor collection & treatment

ODOR COLLECTION & TREATMENT
Covered collection over tanks/workshops▸Odor collection header▸Scrubber
acid + alkali wash
▸Biofilter
600m³ media
▸15m stack, meeting discharge standards

Odor air volume 25,000 m³/h; meets Grade II of GB 14554-93 Emission Standard for Odor Pollutants.

MASS BALANCE

Mass balance

50 t of waste + 15 t of make-up water, outputs are grease, biogas, impurities, grit residue and digestate. This table drives all downstream equipment sizes and revenue calculations.

Daily mass balance (design)

DAILY MASS BALANCE
DirectionMaterialAmountUnitRouting / note
In Food waste50.0t/dEnclosed trucks delivered, weighed on site
Process make-up & wash water15.0m³/dPulping make-up, equipment and floor washing
Out Crude oil/grease1.8t/dInsulated oil tank → for sale (moisture ≤3%)
Biogas3,000m³/dAfter desulfurization → 6,000 kWh power / boiler heat
Inorganic impurities2.0t/dPulper heavy-matter outlet → off-site incineration/landfill
Dewatered grit residue2.0t/dCyclone grit removal → screw press dewatering (moisture ≤60%)
Digestate52m³/dDigestion effluent → land application or discharge
Loss (evaporation, carry-over)~5t/dCarried by odor exhaust and biogas
Water-balance note: pulping needs make-up water, but digestion effluent (52 m³/d) is itself "water". If downstream digestate membrane concentration or land application is arranged, fresh make-up can drop to 5–8 m³/d and water cost becomes negligible. The digestate outlet is the key to closing the loop; we recommend securing a land-application agreement or discharge quota early.
EQUIPMENT GALLERY

Key equipment photos

Photos of the 8 core units in this plan; the models and list item numbers can be matched one-to-one with the equipment list that follows. Click an image to view the original.

About the images:Photos are of the same model of equipment; overall color, platform railings and control positions can be adjusted to site conditions. The digester, biogas upgrading and generator set are custom-built to drawings and are not in the product gallery; the as-built fabrication drawings govern.
EQUIPMENT LIST

Equipment list & quotation

Totaling 39 items in five systems. Unit prices are ex-works incl. 13% VAT (excl. freight, civil works and external electrical). Equipment subtotal RMB 9,506,000.

I. Receiving & pulping system

MECHANICAL PRE-TREATMENT
No.EquipmentModel / specQtyUnitUnit price
(10k RMB)
Amount
(10k RMB)
Notes
1Enclosed receiving hopperV=10m³, hydraulic lid, leachate drainage2pc7.8015.60Including grid and screw discharge
2High-pressure hydraulic pulperZSGJ-5, mechanical shearing + hydraulic scouring2pc37.8075.605 t/h each, one duty one standby
3Pulping outlet screw pumpZJB-11, Q=20m³/h2pc1.503.00One duty, one standby
4Raw-slurry buffer tank agitatorQJB-4, 4kW4pc2.8011.20Anti-sedimentation/stratification
5Slurry feed pumpZJB-11, VFD2pc1.803.60To cyclone grit removal
6Shaftless screw conveyorØ400×80002pc4.809.60Removes inorganic impurities
7Online buffer-tank level/concentration monitoringUltrasonic level + density meter1set3.203.20Interlocked with feed pump
Subtotal121.80

II. Grit removal & oil extraction

SAND REMOVAL & OIL EXTRACTION
No.EquipmentModel / specQtyUnitUnit price
(10k RMB)
Amount
(10k RMB)
Notes
8High-concentration cyclone grit removerXLCS-2, Q=15m³/h2pc6.8013.60Slurry overflows, grit discharges below
9Screw press dewatererZNJ-315, grit dewatering1pc17.8017.80Cake moisture ≤60%
10Constant-temp heating reactorV=20m³, coil heating + agitation + insulation2pc12.6025.2070–80℃ constant temp
11Heating-tank pumpZJB-112pc1.503.00
12Three-phase horizontal disc centrifugeWLL-450, Q=10–12m³/h2pc32.8065.60One duty, one standby
13Insulated oil/grease storage tankV=20m³, electric tracing + insulation2pc8.6017.20Crude oil/grease buffer storage
14Oil discharge / loading pumpKCB-1352pc1.402.80
15Heat exchange unitHot-water/steam dual use, 1.5MW1set11.0011.00Feeds the heating tank
Subtotal156.20

III. Hydrolysis/acidification & anaerobic digestion

HYDROLYSIS & ANAEROBIC DIGESTION
No.EquipmentModel / specQtyUnitUnit price
(10k RMB)
Amount
(10k RMB)
Notes
16Hydrolysis/acidification tankV=250m³, with agitation and insulation1tank32.0032.00HRT≈4d
17Mesophilic anaerobic digesterV=1000m³, steel bolted, gas-tight roof, heating coils2tank78.00156.00HRT≈22d, 35±2℃
18Digestion feed pumpScrew pump, Q=10m³/h VFD2pc4.208.40One duty, one standby
19Side-entry agitator7.5kW, mechanical seal6pc6.2037.203 per tank
20Biogas gas-water separator & collection headerIncluding condensate drain and flame arrester1set13.0013.00
21Dry desulfurization towerIron-oxide desulfurization, one duty one standby2pc8.2016.40Outlet H₂S≤20ppm
22Double-membrane gas holderV=1500m³, membrane constant pressure1set52.0052.00Including membrane, blower, safety valve
23Biogas distribution valve groupFlame arrester, pressure regulation, flow metering1set10.0010.00
24Biogas hot-water boiler1.4MW, for digestion heating1pc28.0028.00Backup heat source
25Hot-water circulation pumps & pipingIncluding insulation1set16.0016.00
26Biogas generator set250kW containerized, incl. waste-heat recovery1set72.0072.00Power + jacket-water waste heat
27Distribution & grid-connection cabinetGenerator connection, low-voltage grid tie1set26.0026.00On-site self-generation/self-use
Subtotal467.00

IV. Odor collection & deodorization

ODOR CONTROL
No.EquipmentModel / specQtyUnitUnit price
(10k RMB)
Amount
(10k RMB)
Notes
28Odor collection branches & headerFRP/304, incl. control valves1set18.0018.00Covered collection over tanks
29ScrubberTwo-stage acid + alkali wash2pc11.0022.00Removes H₂S, NH₃
30Biofilter600m³ media, incl. air distribution1tank46.0046.00Residence time ≥25s
31Odor centrifugal fanQ=15000m³/h, VFD2pc5.5011.00One duty, one standby
32StackH=15m, incl. sampling ports and ladder1tank4.004.00Compliant discharge
Subtotal101.00

V. Control & utilities

CONTROL & UTILITIES
No.EquipmentModel / specQtyUnitUnit price
(10k RMB)
Amount
(10k RMB)
Notes
33PLC centralized control systemSiemens S7-1500 + host PC + HMI touchscreen1set32.4032.40Centralized control-room monitoring
34Field instrumentsLevel/temperature/pH/flow/gas detection1set9.609.60Including combustible gas alarm
35Control cabinets, power cables & trayMNS cabinets + YJV cables1set15.0015.00
36Process piping, valves & supports304 stainless / carbon steel1set22.0022.00
37Platforms, ladders, railings & anti-corrosion insulationHot-dip galvanized + topcoat1set16.0016.00
38Air compressor & air receiver1.0m³/min1set3.603.60Air supply for pneumatic valves
39Fire-fighting & safety facilitiesFire extinguishers, eyewash, signage1lot6.006.00
Subtotal104.60

Equipment subtotal

SUBTOTAL BY SYSTEM
SystemAmount (10k RMB)Share
I. Receiving & pulping system121.8012.8%
II. Grit removal & oil extraction156.2016.4%
III. Hydrolysis/acidification & anaerobic digestion467.0049.1%
IV. Odor collection & deodorization101.0010.6%
V. Control & utilities104.6011.0%
Equipment subtotal950.60100%
QUOTATION

Equipment quotation summary

This quotation covers only the treatment equipment in the process flow diagram, excluding civil works, buildings, tanks and utilities. Unit prices are ex-works incl. 13% VAT; freight and installation/commissioning, if undertaken by us, are priced separately.

Quotation scope

WHAT IS INCLUDED
  • All process equipment across five systems, 39 items (incl. standby units)
  • Equipment body, standard accessories, special tools and spare parts
  • Technical specifications, operation & maintenance manual, factory inspection and pressure-test reports
  • Incl. 13% VAT
  • Civil works, buildings, tanks, equipment foundations and berms
  • Freight, unloading, lifting and installation/commissioning
  • 10kV external line and transformer capacity upgrade
  • Advanced digestate treatment; food-waste collection vehicles

Total equipment price

950.6010k RMB
39 items · incl. 13% VAT · civil works and freight excluded
  • Investment per capacity19.0 10k RMB/(t·d)
  • Equipment investment per tonRMB 576/(t·yr)
  • Annual throughput16,500 t
  • Pricing basisEx-works · incl. tax

If we also undertake these, priced separately (not in the above)

OPTIONAL
ItemBasisAmount (10k RMB)
Freight2% of equipment cost19.01
Installation & commissioning (incl. site supervision, integrated commissioning and operator training)8% of equipment cost76.05
Both subtotal95.06
Why civil works are not priced: buildings, tanks and foundations depend heavily on site investigation, site conditions and local construction costs; the same equipment can have civil works that differ by a factor of two between plants. Equipment price is fixed; civil works can only be measured from drawings. This quotation is responsible only for the equipment; the civil works may be tendered by the owner or entrusted to us separately.
OPERATING COST

Operating cost

Allocated over 16,500 t/yr. Basis: excluding depreciation and financing, including power, water, chemicals, labor, maintenance, and digestate/residue disposal.

Cost breakdown

OPEX BREAKDOWN
Cost itemRMB/t10k RMB/yrBasis
Electricity (at RMB 0.65/kWh)71.5118.0Plant power 5,500 kWh/d; biogas generation offset shown under revenue
Water (process make-up & wash)1.83.0Make-up 20 m³/d × RMB 4.5
Chemicals (desulfurization, deodorization, flocculation)18.029.7~RMB 900/d
Labor wages & benefits87.3144.0Staff 15 × RMB 8,000/month
Equipment maintenance & spares16.126.62.5%/yr of original equipment value
Digestate disposal27.545.452 m³/d × RMB 25/m³ (land application or discharge)
Inorganic impurities & grit off-site6.711.14.0 t/d × RMB 120/t
Testing, monitoring & admin4.88.0Environmental online monitoring, routine testing
Total operating cost233.8385.8
Depreciation (15-yr straight-line, residual 0)38.463.4Based on equipment price RMB 9,506,000
Full cost272.2—
Operating cost per ton
233.8RMB/t
Industry same scale RMB 210–280/t
Full cost per ton
272.2RMB/t
Incl. depreciation, excl. loan interest
Revenue per ton
525RMB/t
Grease + power + tipping fee + digestate
REVENUE & PAYBACK

Revenue & payback

Three revenue streams: selling oil, selling (saving) power, and collecting the tipping fee. The tipping fee is a policy variable, so a sensitivity analysis is shown separately below.

Annual operating revenue

ANNUAL REVENUE
Revenue itemQuantityUnit price10k RMB/yrNote
Crude oil/grease sales594.0 t/yrRMB 7,250/t430.651.8 t/d × 330 days
Biogas power (offset purchased power)1,980,000 kWh/yrRMB 0.65/kWh128.706,000 kWh/d × 330 days, self-use
Waste treatment service fee16,500 t/yrRMB 180/t297.00Per local subsidy standard, negotiable
Digestate fertilizer sales——10.00At a conservative value
Total annual operating revenue866.35

Revenue mix

REVENUE MIX
OilPowerTipping
Crude oil 430.65 Biogas power 128.70 Tipping fee 297.00 Digestate 10.00

Oil and the tipping fee are two legs: oil price follows the market (recent crude oil RMB 6,000–8,000/t), while the tipping fee is set by local fiscal subsidy policy. Relying on oil sales alone, the project is marginal; once the tipping fee arrives, payback shortens markedly.

Bottom line

BOTTOM LINE
Annual operating revenue866.35 10k RMB
Annual operating cost-385.8 10k RMB
Annual net operating cash flow480.55 10k RMB
Annual depreciation-63.4 10k RMB
Annual pre-tax profit417.18 10k RMB
Static payback (on equipment price)2.0 years

Sensitivity: at different tipping fees

SENSITIVITY
ScenarioTipping fee (RMB/t)Net cash flow (10k RMB)Payback (equipment basis)
Purely market-based collection (no tipping fee)0183.55.2 years
Tipping fee RMB 120/t120381.52.5 years
Tipping fee RMB 180/t (baseline)180480.52.0 years
Tipping fee RMB 240/t240579.51.6 years

Note: payback is computed as "equipment price ÷ annual net operating cash flow", excluding loan interest and income tax. If the owner’s civil works, buildings, tanks and utilities are included (typically RMB 8–9 million for this scale), total project investment is ~RMB 18 million, and the payback for the four scenarios above is about 9.9 / 4.7 / 3.8 / 3.1 years respectively. Civil works are outside this quotation and are provided for investment-decision reference only.

SCOPE & TERMS

Supply scope & commercial terms

Writing down "who is responsible for what" clearly is more valuable than pushing the price down.

Our supply scope

INCLUDED
  • Full-line equipment for receiving, pulping, grit removal, heating and three-phase oil extraction
  • Hydrolysis/acidification tank, 2×1000m³ mesophilic digester with agitation and heating systems
  • Biogas upgrading (desulfurization, gas-water separation), 1500m³ double-membrane gas holder
  • 250kW biogas generator set (incl. waste-heat recovery), 1.4MW biogas boiler
  • Odor collection, scrubber, 600m³ biofilter, 15m stack
  • PLC centralized control, field instruments, control cabinets and power cables
  • Process piping/valves, platforms/ladders, anti-corrosion insulation
  • Transport, installation/commissioning, operator training (2 weeks)

Not included in this quotation

EXCLUDED
  • Civil works, steel-structure buildings, tanks, equipment foundations and berms
  • 10kV external line and transformer capacity upgrade
  • Advanced digestate treatment (membrane concentration / MBR), to be discussed if needed
  • Food-waste collection vehicles and bins
  • Site landscaping, perimeter wall, guard house, weighbridge
  • Third-party costs: EIA, energy assessment, acceptance, etc.
  • Operating-period water, power, chemicals and labor
  • Work stoppage due to force majeure or owner reasons

Commercial terms

COMMERCIAL
Quotation validity30 days (steel and stainless prices are volatile; re-pricing needed beyond this)
DeliveryShipment 90 days after contract effectiveness and advance payment; digester tanks 120 days
Payment terms30% advance / 40% before shipment / 25% on installation completion / 5% retention
WarrantyEquipment 12 months (wearing parts excluded); digester tanks 5 years
Pricing basisIncl. 13% VAT, incl. freight (prefecture-level cities in China)
Acceptance criteriaContinuous 72-hour full-load trial; throughput, oil recovery and biogas output meet design

To be provided by the owner

BY OWNER
  • Site general layout, geotechnical report, confirmed power supply capacity
  • Feed lab data (moisture, oil content, impurity rate)
  • Digestion effluent outlet (land-application agreement / discharge quota)
  • Grease off-take intent (recommend locking the buyer and price in advance)
  • Temporary construction water/power and site access road conditions
Lead-time note: equipment delivery is 90 days (digester tanks 120 days); civil works are organized separately by the owner (~120–150 days) and can run in parallel. Installation starts once civil works are ready; from equipment shipment to oil output is ~3–4 months. The digester needs on-site assembly and a water-tight test before sludge inoculation, and reaching design output needs another 60–90 days.
Notes:This plan is based on the process flow diagram provided by Mr. Liao; equipment sizes use typical design values for 50 t/d food waste. If actual feed oil content exceeds 4% or the impurity rate exceeds 6%, the pulper and three-phase separator sizes must be rechecked. All prices are estimates; the official offer is the technical agreement and written quotation confirmed by both parties.。
Zhucheng Xinridong Machinery Factory
Food Waste Treatment Equipment · Plant-scale process-line EPC · Retrofit & upgrade of existing plants
Project contact
Manager Guan
Phone / WeChat
150 6449 6759
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