Present Solutions for Sewage Sludge Disposal

Conventional methods of sewage sludge disposal – land filling, ocean dumping, compost and incineration, are causing irrevocable environmental damage. This is seen in the contamination of underground water reservoirs and fertile land, the pollution of oceans and the emission of hazardous gases into the air. Sludge fertilizer, which is already banned in some European countries, such as Holland, will be banned in Switzerland by 2005. The move is in response to growing concern about residues in the sludge, particularly synthetic hormones and some pharmaceutical compounds. Today, an average of 40% sludge is used in agriculture with the rest being incinerated.

Changing regulations are the catalyst driving the wastewater and sludge treatment market. These regulations are driving the end-users to search for final treatment methods other than incineration, agricultural use, landfills and ocean dumping. Due to a decrease in the disposal sites for industrial and municipal sludge, and due to national and international regulations, it will soon be more common to reuse primary and secondary sludge as a sustainable energy source, such as fuel for industrial plants.

Pyrolysis and gasification, like incineration, are options for recovering value from sewage sludge by thermal treatment. Both pyrolysis and gasification turn sewage sludge into energy-rich fuels by heating the sludge under controlled conditions. Whereas incineration fully converts the input sewage sludge into energy and ash, these processes deliberately limit the conversion so that combustion does not take place directly. Instead, they convert the sewage sludge into valuable intermediates that can be further processed for materials recycling or energy recovery.

Pyrolysis and gasification offer more scope for recovering products from sewage sludge than incineration. When sludge is burnt in a modern incineration the only practical product is energy, whereas the gases, oils and solid char from pyrolysis and gasification can not only be used as fuel, but also purified and used as a feedstock for petrochemicals and other applications. Obviously, there is a growing demand for sludge management technologies capable of: 1). Meeting increasingly stringent regulatory requirements. 2.) Effectively utilizing potential for material and/or energy recovery.

The BioPetrol Solution

Introduction

Measures to be implemented to resolve the problem of sewage sludge that contain a high degree of organic matter could primarily aim at recycling it through a thermo chemical pyrolysis process in order to recover hydrocarbons that make up the structure of sewage sludge. Pyrolysis of sewage sludge produces oil, gas and char products. The pyrolysis oils have also been shown to contain valuable chemicals in significant concentrations and hence may have the potential to be used as chemical feedstock. The production of a liquid product increases the ease of handling, storage and transport.

The technology, improved by BioPetrol Ltd. (patent pending) is capable of processing carbon wastes, other than sewage sludge, including agri-wastes, bagasse, pulp and paper residues, tannery sludge and other end-of-life products such as plastics, tires and the organics in municipal solid waste.

The process of low temperature thermochemical conversion of municipal sewage sludge to oil is a new technology in developed countries. The amount of investment is still less than the amount invested in the sewage sludge incineration process, and the operational economy of the process is obviously superior to incineration.

The BioPetrol, Ltd. integrated thermochemical process (patent pending) recovers about 1,100,000 Kcal from each 283 kg of sewage sludge 90% D.S. after the thermal evaporating of 717kg water from each dewatered ton (1,000 kg) of sewage sludge 26% D.S.

The BioPetrol process begins with sewage sludge at 90% D.S. Sewage sludge drying equipment is used commonly for the evaporative removal of interstitial water from the sludge. Numerous drying technologies exist on the market.

Market Analysis and Strategy

Three potential products/services:

1. Disposal of Sewage Sludge – Disposal of sewage sludge comprises over 30% of wastewater treatment plants’ budget. Customers of this service are local communities. They are willing to pay top dollar for the disposal of their sludge. For example: Holland $50-$90 per ton, U.S., Canada and Australia, up to $150 per ton. The US produces 25 million tons of sludge annually (2001).

2. Synthetic Crude Oil – Excess crude oil, beyond what is being recirculated to run equipment A+B is about 30 kg per 1 ton sewage sludge 90% D.S. Oil energy = 8,900 Kcal/kg same as diesel oil used in heavy industry. There are references in professional literature to numerous valuable chemicals in significant concentration that are present in pyrolysis oils.

BioPetrol Ltd has on board, as a shareholder, an internationally renowned scientist-academician to address this issue.

3. Selling the Technology - With the completion of the development of the process and equipment for its operation, BioPetrol. Ltd. will have the technology to sell to world markets. Potential markets are water authorities, municipalities, wastewater treatment plants, entrepreneurs, sewage sludge disposal contractors, sludge drying operators.

BioPetrol, ltd. has been awarded a grant of $300,000 for a period of 2 years by Israel’s Office of the Chief Scientist to conduct advanced R&D. The company has concluded and proved the viability of the process and is now on the verge of constructing a demonstration pilot for a continuous process.

BioPetrol is seeking an investment of US$400,000 for the completion of the demonstration pilot. A business plan is available for further details.

Technology

The technological processes at issue in the Bio-Petrol project belong to the sphere of liquefying carbon-rich solid fuels. The liquefaction processes common today comprise two stages:

1. Thermal breakdown of the molecular structure to create radical fractions different in size.

2. Stabilization of the radicals by recombining themselves or by redistribution of hydrogen from the raw material itself or by hydrogen that is introduced from outside (molecular hydrogen or from hydrogen-donor matter).

Bio-Petrol Company has carried out R&D work which has resulted in the formulation of a suitable process for producing synthetic oil from sewage sludge with larger output than that obtained from the common process-i.e. pyrolysis. By integrating familiar liquefaction methods the company developed a process of high utilization of the organic matter that is in the sewage sludge that produces oil and gas in larger quantities and of better quality.

Project Team

Ari Sofer – Founder
Sewage sludge disposal specialist with 20 years experience working with wastewater treatment plants both in the United States and Israel. Graduate of the Univ. of Calif. – Berkeley, College of Environmental Design.

Dr. Yafim Plopski – Chief Scientist
Holds a Ph.D in chemical and technology of fuels. Over 30 years experience in the field of oil and petrochemical recovery technology in both Russia and Israel. Has 40 relevant publications and patents on the subject.

Dr. Alexander Rogov – Chief Researcher
Ph.D in chemistry and gas and fuel technology. Has written 25 articles and has more than 60 patents in this field.

Professional Board

Professor Ze’ev Eisenshtat – Member of the National Committee for Fuels and Oils: regulation and standards. Was a consultant to Chevron Oil Field Research Company and head of Hebrew University’s Energy Research Center. Published over 300 relevant papers on the subject.

Dr. Amit Mor – Received his Ph.D in economics, energy and the environment from Pennsylvania State University. Was the consultant to the World Bank in Washington for energy and environment infrastructure projects and in policy planning for reforms in the environment, electricity, oil and natural gas.