Sludge Watch ==> UK Drying or Gasifying sludge - problems with drying process

[Maureen Reilly]

Thermal processing: building success from coke to incineration

According to its website, Otto Simon is a young, dynamic company whose aim 
is to offer excellentlong-term service to its customers.

Which is quite an objective for an organisation just two years old. However 
the clue is in the name and many process engineers will be familiar with the 
Otto Simon Carves company from which Otto Simon was created.

“As you might expect from the name, our technical knowledge is based on a 
long history of coke making and its wide range of processes for handling 
dirty product gas and recovering chemicals. These have then been used as a 
basis for successfully diversifying into related technology areas over the 
last 20 years,” notes Haywood.

So today the company specialises in consultancy and design/build services 
for the steel, water and energy industries. Its diverse technological skills 
all relate to thermal treatment and related technologies and include 
pyrolysis, gasification, incineration, drying, heat recovery, gas cleaning, 
wastewater treatment and more.

In terms of its traditional business, Otto Simon has a co-operation 
agreement with Uhde, the world's largest supplier of coke making technology, 
covering the UK market. In addition, through this partnership the company 
provides subcontract services on Uhde projects in many other countries.

However, as Haywood explains, the coke market is facing radical changes. 
“About 20–30 years ago there were many companies working in this area, with 
several employing thousands of staff. Today, most of these companies are 
part of the Uhde group and employees in the cokemaking division number in 
the hundreds. However the recent upturn in the steel industry, the gradual 
reduction in cokemaking capacity over the years and the demand for coke in 
China has significantly increased the demand for coke and created a 
resurgence in cokemaking activity. Many companies are either building new 
facililities or extending/ upgrading existing facilities and the result is 
that Uhde and its partners are extremely busy. However, steel is a cyclical 
industry and while there will always be some work in the sector, we are 
using our relevant expertise to get involved in other areas of thermal 
treatment.”

For example, one of the company’s key projects in 2005 was the development 
for a gasification plant and power generation facility in London that is 
designed to handle fuel recovered from municipal waste.

“We were involved with the conceptual and basic design, IPPC application and 
the planning application. You have to remember that cokemaking is a 
pyrolysis/gasification process and the coking and associated gas cleaning 
processes for handling dirty gases and recovering coal chemicals are very 
relevant to gasification.”

The company has also been involved in many other thermal treatment and 
related energy projects. In the past two years this includes consultancy and 
design work for several sewage sludge fluidised bed incineration plants in 
the UK, plus engineering, problem solving and commissioning for sludge 
drying plants in the UK and a very large facility in the USA. Other related 
projects have included heat recovery and power generation schemes.

“Essentially we are finding that our cokemaking expertise and past 
experience of designing and building incineration and drying facilities has 
put us in a unique position to be able to offer significant hands on 
experience for a range of thermal treatment technologies.”

It’s no surprise, therefore, that Haywood believes the future is going to be 
much more closely related to incineration and its related technologies.

The case for incineration

“Incineration generally has a poor public perception, but modern fluidised 
bed incineration is a well proven and reliable process for sludge treatment 
plus emissions to atmosphere are very low. Also, once it is built, you have 
a secure facility that gives an inert waste product. In the last 10 years in 
the UK, for example, a few sewage sludge incinerators have been built for 
major centres of population such as Manchester, London and Birmingham. 
However, outside large urban areas and even in some cities many companies 
have used sludge drying. Typically the sludge is dried to 90percent and the 
product can be used as a fuel or for agriculture use. The upside is that you 
get a useful product and the capital cost is lower. The downside is that 
there is still a product to dispose of and suitable outlets are not 
guaranteed. In addition drying uses a large amount of energy which is 
becoming increasingly expensive where as modern incinerators do not require 
fuel for normal operation and actually recover energy which can be used for 
heating or to produce electricity.”

“My own view is that although many water companies have tended to go for 
sludge drying in recent years there will be a tendency to build more 
incinerators in the future. In addition to the reasons given above it has 
been found that drying has been more problematic than expected. In general 
most people thought that drying is a simpler process than incineration. 
However in practise there have been significant safety issues and the nature 
of UK sludges has created serious problems for several drying plants.”

So for treatment of sludge cake the options are drying, incineration and 
gasification: “Gasification is acceptable from a public perception 
standpoint but compared to incineration it is an expensive alternative for 
sewage sludge and is not well proven. A typical incineration plant producing 
3t/h of dry material costs E30–50million. A sludge drying plant of similar 
capacity costs E10–15million. A gasification plant still requires drying 
while the cost of the gasification plant is going to be similar to 
incineration if it is going to achieve similar energy efficiency and 
emission standards. In addition if it is true pyrolysis or gasification 
there is normally still char, tar and ammonia liquors which require 
treatment or a suitable outlet.”

It’s all about reputation

In some European countries, it can be difficult for smaller companies to 
work directly for the customer and thereby establish a close relationship. 
Haywood blames this on the framework agreements that clients establish with 
larger companies.

“Under such agreements, a major contractor is appointed to oversee every 
aspect of a project, often for many years. This company then subcontracts 
aspects of the work to others. So like many other small suppliers we no 
longer have a procurement system under which we can link directly with the 
actual customer. Ten years ago we would have had many more opportunities to 
do this.”

Bearing in mind this obstacle to direct customer contact, how then does a 
small operator such as Otto Simon stay in business? Shouldn’t it be absorbed 
by the big players who want to be able to offer every possible technological 
expertise a customer might require?

“From our standpoint, the key to success lies in establishing a reputation 
for know how and technical expertise. This is a matter of marketing, making 
the right contacts and doing excellent work so that we get repeat business.”

“In several cases we have been able to develop relationships with larger 
contractors and consultancies who have been willing to accept that we have 
specific skills in thermal treatment which compliment their own 
capabilities. The result is that the end client gets the best service.”

He says there are also signs that the company's expertise is being 
recognised by other large companies and more doors are opening as a result. 
At the same time, its track record is now giving more opportunities to work 
directly with some clients.

Haywood believes that this will continue to happen because his staff offer 
significant practical experience for consultancy to the water and other 
industry for thermal processes: “We have designed, built and commissioned 
these plants. Most of our staff are in their 40s and 50s and have process 
backgrounds. A lot of other consultants are not able to offer this 
practical, hands-on experience for thermal treatment.”

As well as the challenge of finding new thermal processing business, Haywood 
also faces a business theory challenge. Otto Simon currently employs 30 
people and management textbooks are littered with case studies of successful 
companies who expanded beyond this size only to flounder in the face of the 
increased complexities of organisational structures.

“Our vision is to continue to grow, but not get to the stage where we need 
another layer of management. We know where we want to be: which is to cover 
all of our disciplines, have highly capable core skills and service our 
clients extremely well,” he concluded.

Otto Simon is based in Cheadle, England. www.ottosimon.co.uk

http://www.engineerlive.com/european-process-engineer/interview-opinion/16617/thermal-processing-building-success-from-coke-to-incineration.thtml