1. INTRODUCTION VAN MARIS BIO-DIGESTION TECHNOLOGY

CMTS Maris Projects B.V. has more than 30 years of experience as a developer. Over the last decade there is vast amount of experience acquired about the production of energy carriers like biogas, ethanol, methanol and bio-diesel made from waste of energy vegetation. With the experience as a developer and the use of waste energy, Maris conducts projects all over the world. Maris also owns a well equipped laboratory which is available to assist customers carry out simulations and various testing on bio digestion processes using differing feedstock.

2. INTRODUCTION DIGESTION

In a biogas installation the biomass will be brought to an oxygen free room. Through the digestion, biogas will be generated. Biogas contains a large proportion of methane gas that can be converted to heat and electricity.

2.1 APPLICATION POSSIBILITIES

Digestion can be applied to many different organic materials like, animal manure, solids from wastewater treatment, materials from the positive list, grain and corn, but also from kitchen waste and rest flow from food and the luxury industry.

2.2 ADVANTAGES OF A BIOGAS INSTALLATION

The financial efficiency of a biogas installation depends on the following aspects:

	Organic residues of many different industry van be digested
	The system works under liquid conditions
	The production of green electricity and thermal energy
	Low emissions
	Killing germs, bacteria and weed
	The flow is easy to stabilize. The minerals are in the solid fraction
	The use of fertilizers can be reduced when the manure substance is tailored to size. This will supply an energetic CO2 emission
	Because there will be no oxygen added the chances of N2O is nil
	Because there will be no oxygen added the chances of N2O is nil
	High-quality conversion of problematic rest flows or superfluous product flows

3. PROCESS STEPS IN THE DIGESTER

3.1 RESEARCH BIOMASS

Not all biomass is adequate to serve as feed for the production of biogas. That is the reason why biomass supply is analyzed on what kind of bacteria colonies can be used and what kind of treatment is necessary. The potential energetic output will be determined by the following parameters:

	Content of dry substance
	Heavy metals
	Amount of nitrogen
	Amount of potassium

3.2 SUPPLY AND STORAGE OF BIOMASS

When the parameters of the supplied biomass are determent the biomass will be briefly stored. The biomass can be mixed with other supply streams for an optimum of digestion.

3.3 TREATMENT

The treatment exists from a physical or a biological nature. The collected biomass streams will be mixed for an optimum of digestion.

First of all the non digestible parts are separated from the flow before the flow enters the digester. The required time for this treatment depends of the origins of the biomass. Then the stream continues its journey to the hammer mills were it will be smashed to tiny bits from 1 or 2 mm. This way the contact area increases so the bacteria can work faster.

3.4 THERMAL DISINTEGRATION

By means of thermal disintegration any unwanted and aggressive micro-organisms will be removed so that the bacteria has a conducive environment to carry out its in the digester. The disintegration takes place at a minimal temperature of 70oC.

3.5 DIGESTION

In the digester the bacteria convert the biomass into methane gas. The carbon connections are cut to smaller pieces by different genus of bacteria.

All these steps can be summarized into two main phases: hydrolysis and digestion. The technology of Maris Projects separates these two main phases because the optimum conditions of both phases are completely different.

A digester works best when there is a stationary condition without many variances. Because the process is aimed for an optimum feed of billions of bacteria, it can’t be stopped for any reason. For this reason the digestion process continues 24/7 for 52 weeks a year.

3.6 THE MAIN PRODUCT: BIOGAS

During the digestion, biogas is formed. Dependable on the energy input from the incoming flow (substrate), some amount of gas/substrate is formed. By flows which are energy rich 200m3/ton substrate can be formed. Roughly said biogas exists 2/3 of methane, 1/3 of CO2 and some spores of other gasses. Dependable of the composition from the substrate, about 1 per cent H2S is formed.

3.7 GAS TREATMENT

From the biogas, water and H2S most be separated. The water condensates when the gas is cooled. By adding oxygen, the bacteria can convert H2S to S and H2O. As a result the sulfur crystallizes and falls down as a solid substance.

3.8 GAS ENGINE AND WKK

The produced gas will generally be used for generating electricity and heat. The gas engine is adapted for a lower calorie gas compared to fossil natural gas. With a generator the electricity is generated and most of the electricity can be connected to the grid to earn revenue. With the production of electricity about 40% will be generated to electricity and 60% heat. The heat is used for containing the temperature at the digestion tank. The rest of the heat can be sold to local buyers.

3.9 MEASUREMENT - AND CONTROL ENGINEERING

Biological processes are very sensitive for disruptions. Therefore it’s very important to have a well organized and working monitor system where imPORT 61,6,68,50,129,3 ulk part of the organic bound nitrogen is in mineral form.

Through the disintegration the manure substance has less harmful bugs and weed seeds than normal manure.