# How does a membrane filter press reduce dryer fuel and CO2 in a chemical unit?

Canonical: https://senseible.earth/answers/membrane-filter-press-drying-wood-saving

By squeezing the cake to 38% moisture instead of 65%, so the dryer has less water to boil off. BEE's Ahmedabad report cuts drying from 72 to 49 hours a batch and wood by 241.5 t a year. Cost Rs 24.20 lakh, payback 3.33 years (2010). Wood CO2 is biogenic, so Scope 1 falls only about 7 t.

## Where the saving starts

A recessed plate filter press leaves cake at about 65% moisture, unevenly from plate to plate. A 40-plate membrane press inflates a membrane behind each cake at 8 to 10 kg per sq cm and presses more liquid out, to about 38%. Every kilogram of water squeezed out is a kilogram the dryer does not evaporate.

## The batch BEE costed

- 1,280 litres a batch, 150 batches a year.
- Hot air generator burning 70 kg of wood an hour.
- Drying after a conventional press: 72 hours, 5,040 kg of wood, 3.94 kg per litre processed.
- Drying after a membrane press: 49 hours, 3,430 kg of wood, 2.68 kg per litre.
- Saving: 1,610 kg a batch, 241.5 t a year.

## Money and payback

- Equipment Rs 19.89 lakh, total project Rs 24.20 lakh.
- Wood at Rs 3,000 a tonne: about Rs 7.26 lakh a year.
- Payback 3.33 years. The report counts no extra electricity; ask whether the squeeze pump or compressor adds any, and take it off the saving.

## What it does to your carbon figures

The report claims 227 t of CO2 saved. That is wood CO2, which is biogenic and reported outside Scope 1. The methane and nitrous oxide from 241.5 t of wood, which do count, are about 7 t CO2e. So Scope 1 falls by about 7 t, and biogenic CO2 by about 420 t, shown separately.

If your dryer runs on coal, oil or gas instead, the same moisture cut would show as a large fossil saving. Work it out with your own fuel per batch.

## 150 batches a year (estimate)

- Wood saved: (5,040 minus 3,430) kg x 150 = 241.5 t
- Scope 1 methane and nitrous oxide avoided: 241.5 x 0.030 = 7.2 t CO2e
- Biogenic CO2 avoided, reported separately: 241.5 x 1.75 = 422 t
- Drying time freed: 23 hours a batch, about 3,450 hours a year

Wood at IPCC 2006 defaults (15.6 GJ per tonne; 112,000 kg CO2, 30 kg methane, 4 kg nitrous oxide per TJ) and AR6 warming potentials.

## What Senseible does here

Senseible reads fuel and power bills into monthly CO2 records. It has no built-in wood factor, so log wood by weight and apply the figures worked out here. The green loan check shows how to present a project like this to a lender.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Efficient 96-tray dryer](https://senseible.earth/answers/efficient-tray-dryer-wood-saving-chemical-unit)
- [Ahmedabad chemical cluster footprint](https://senseible.earth/answers/ahmedabad-chemical-cluster-gas-carbon-footprint)
- [Biomass boilers: methane stays in Scope 1](https://senseible.earth/answers/biomass-boiler-ch4-n2o-still-scope-1)

Sources: [BEE, Detailed project report: membrane filter press, 40 plates, Ahmedabad chemical cluster (2010, SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/Ah_40_1.pdf), [IPCC 2006 Guidelines, Volume 2 Energy, Table 1.2 (net calorific values) and Chapter 2 tables](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [GHG Protocol Corporate Standard (biogenic CO2 reported separately from the scopes)](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-10-31. Equipment figures are from a BEE SME programme project report; costs and paybacks are at that report's prices. Recheck with today's fuel and power prices and a current quote.