Boolean search strings for process engineers: chemical, semiconductor, manufacturing and biopharma, and the business process collision

"Process engineer" names at least four different jobs: designing and optimizing units in a refinery or chemical plant, running an etch or lithography step in a semiconductor fab, improving a production line in discrete manufacturing, and scaling up a drug or biologic under good manufacturing practice. When the client wants the chemical engineering degree itself, our Boolean search strings for chemical engineers start from the degree and the plant instead of the title. The title also collides with business process roles, process technicians and, on databases that fill in word endings, processing and processor titles. Search the industry's own tools and vocabulary (Aspen HYSYS and HAZOP, etch and wafers, PFMEA and SPC, bioreactors and cGMP), quote "process engineer," and exclude the neighbors. As of November 2026, LinkedIn supports AND, OR, NOT, quotes and parentheses but no wildcards.

Below are ten strings by kind of process work, and what LinkedIn, Indeed, Dice and Google support as of November 2026. For equipment and plant design, see Boolean search strings for mechanical engineers; for medical device manufacturing, see Boolean search strings for biomedical engineers.

Industries, tools and credentials that change what a process engineer search finds

• Process safety has its own vocabulary. OSHA's 29 CFR 1910.119, the process safety management standard for highly hazardous chemicals, includes process hazard analysis, operating procedures, pre-startup safety review, mechanical integrity, management of change, incident investigation and compliance audits, as of November 2026. Chemical process engineers write PSM, PHA, HAZOP, MOC and PSSR, so those words separate them from manufacturing process engineers.
• GMP words mark pharma and biotech. The FDA's CGMP regulations page lists 21 CFR Parts 210 and 211 for drugs and Part 600 for biological products. Profiles write "cGMP," "GMP," "process validation" and "tech transfer."
• The PE license is uncommon and specific. NCEES's PE Chemical exam page says the exam is computer-based, given year-round at Pearson test centers, has 80 questions and is designed for engineers with at least four years of post-college experience, as of November 2026. Licenses come from state boards, which NCEES lists in its licensing board directory. Search "professional engineer" or "pe license," never the bare letters PE, which also mean physical education and private equity.
• Six Sigma credentials are optional evidence. ASQ offers the Certified Six Sigma Black Belt (CSSBB) and the Green Belt (CSSGB). Many profiles list belts from employers or other trainers, so search "six sigma black belt" alongside the ASQ names and never require one.

Ten Boolean strings by kind of process work

Swap in the unit, process step and metro from your own intake; these are examples.

Chemical, refining and process safety

1. Chemical process engineer — LinkedIn general search
("process engineer" OR "chemical process engineer" OR "process design engineer" OR "chemical engineer") AND ("aspen hysys" OR "aspen plus" OR hysys OR chemcad) AND ("p&id" OR "p&ids" OR pfd OR "heat and material balance") NOT ("business process" OR recruiter)

2. Process safety and PSM — LinkedIn Recruiter, Job titles + Keywords filters
("process engineer" OR "process safety engineer" OR "psm coordinator") AND ("process safety management" OR "1910.119" OR psm) AND (hazop OR "process hazard analysis" OR "management of change") NOT (scrum)

3. Refinery unit process engineer — Indeed Smart Sourcing
("process engineer" OR "refinery process engineer" OR "unit engineer") AND (refinery OR "fluid catalytic cracking" OR hydrotreating OR "crude unit") AND skill: ("aspen hysys" OR "process simulation")

Semiconductor fabs

4. Semiconductor process engineer — LinkedIn general search
("process engineer" OR "etch process engineer" OR "lithography process engineer" OR "thin film process engineer" OR "cmp process engineer") AND (etch OR lithography OR cvd OR pvd OR cmp OR diffusion) AND (wafer OR wafers OR fab OR "300mm") NOT (recruiter)

5. Process integration or yield engineer — LinkedIn Recruiter, Keywords filter
("process integration engineer" OR "yield engineer" OR "yield enhancement engineer") AND (wafer OR feol OR beol OR "front end of line") AND (spc OR "defect reduction" OR "yield improvement")

Manufacturing and biopharma

6. Manufacturing process engineer — LinkedIn general search
("manufacturing process engineer" OR "process engineer" OR "manufacturing engineer") AND (pfmea OR "control plan" OR spc OR "process capability") AND ("lean manufacturing" OR "six sigma" OR kaizen) NOT ("business process" OR "process improvement analyst" OR recruiter)

7. Process engineer with a Six Sigma belt — LinkedIn Recruiter, Keywords filter
("process engineer" OR "manufacturing process engineer") AND ("certified six sigma black belt" OR cssbb OR "six sigma black belt" OR "certified six sigma green belt") AND (dmaic OR minitab OR jmp)

8. Biopharma process engineer — LinkedIn general search
("process engineer" OR "process development engineer" OR "msat engineer" OR "manufacturing sciences engineer") AND (upstream OR downstream OR bioreactor OR chromatography OR "single-use") AND (cgmp OR gmp OR "process validation" OR "tech transfer")

Licenses and the public web

9. Licensed chemical engineer — LinkedIn general search
("process engineer" OR "chemical engineer" OR "process design engineer") AND ("professional engineer" OR "pe license" OR "licensed professional engineer") AND ("process design" OR "pe chemical" OR "chemical engineering")

10. Public LinkedIn profiles by tool and metro — Google X-ray
site:linkedin.com/in "process engineer" "aspen hysys" "houston" -jobs -recruiter

What LinkedIn, Indeed, Dice and Google actually support

LinkedIn's Boolean help page says, as of November 2026, that AND, OR and NOT must be typed in capitals, that quotes mark exact phrases and parentheses are the only grouping symbols, and that wildcards are not supported, so "p&id" and "p&ids," or "wafer" and "wafers," each need writing out. It evaluates quotes first, then parentheses, NOT, AND and OR. LinkedIn Recruiter's Boolean page lists Job titles, Companies, Skills and Assessments and Industries as Boolean filters and warns that too many facets in one query can cause a search result issue; the Industries filter is a cleaner way to separate refining from semiconductors than a long keyword block.

Indeed's Smart Sourcing guide shows AND, OR, NOT, quotes and parentheses, plus skill: for the skills section and fieldofstudy: for education, so fieldofstudy: "chemical engineering" narrows an early-career search. String 3 copies the guide's own spacing. Dice's Boolean guide says its database fills in word endings, so the shortest form of a word also finds longer ones; on Dice a bare process can widen to processing and processor, which is one more reason to quote "process engineer." Google's search operators page documents quotes, site:, the minus sign and filetype:, but not OR, so string 10 uses none.

Narrowing by industry, site role and stage

Ask the client where the engineer sits. Plant and fab engineers support a running process: they write about yield, downtime, troubleshooting, turnarounds and on-call support. Design and project engineers, often at engineering contractors, write about front-end engineering design, detailed design, equipment sizing and startup. Development engineers in biopharma write about scale-up and tech transfer to a commercial site. Each is a different hire, and the words on the profile usually say which.

Then narrow by the unit or step the client runs: a distillation train, a hydrotreater, a dry etch tool set, an injection molding line or a monoclonal antibody purification suite. For seniority, look for "led the HAZOP," "debottlenecked," "owned the tool set," "startup" and "capital project," over "supported." Use LinkedIn's premium filters for Years of Experience and Seniority Level if you have Recruiter or Sales Navigator; the page lists them only there, as of November 2026.

False positives worth excluding with NOT

• Business process roles. Business process analysts, BPM consultants and process excellence leads share the word. Exclude "business process" and "process improvement analyst," and keep continuous improvement engineers, who often are the manufacturing hire.
• Processors. Loan processors, claims processors and payroll processing staff appear when a database fills in word endings. Quote "process engineer" and require an industry term.
• Professional Scrum Masters. Scrum.org's Professional Scrum Master I certification is written PSM I, the same letters as process safety management. Exclude "scrum" in PSM searches.
• Process technicians and operators, for engineering roles. They run the same units and tools on shifts and list the same words. They are the right pool for technician searches; for engineers, require a simulation, design or data tool.
• Process servers and food processing staff on Google. Legal process servers and food processing plant workers show up in X-ray results. Keep "process engineer" in quotes and add "-server."
• Recruiters and trainers. Exclude "recruiter," "talent acquisition" and "instructor."

None of these strings targets or excludes anyone by age, sex, race, religion, national origin, disability or veteran status, and yours should not either; leave out proxies such as graduation years and names.

A worked example: three passes on a chemical plant debottlenecking search

An invented search, shown as it actually gets narrowed.

The tool block removed the other industries; the project words found engineers who have changed a running unit rather than only kept it running. Widen to refining before you drop the debottlenecking block.

What a search cannot verify

A string can find someone whose profile names the right tools, units and safety work. It cannot show whether they led the HAZOP or attended it, built the simulation or ran someone else's model, or whether a listed PE license is current; check that on the state board's lookup through the NCEES directory. Then use the mechanical engineer phone screen questions as a model for the technical call, the interview guide for manufacturing roles for plant interviews, and the 30-60-90 day plan for plant managers when the process engineer will step into plant leadership.